1. Field of the Invention
The present invention relates to a plane light source device, and particularly to a front light plate.
2. Description of the Related Art
With the advancement of the flat display technology and due to the flat display apparatuses having advantages of light in weight, small in size and low power consuming, the flat display apparatuses have become more and more popular. In general, the flat display apparatuses include liquid crystal display (LCD) apparatuses, plasma display panel (PDP) apparatuses, organic light emitting diode (OLED) display apparatuses and electrophoretic display (EPD) apparatuses, etc., wherein the LCD apparatuses are more popular than others.
In general, the common LCD apparatus is a transmission LCD apparatus. The transmission LCD apparatus using a backlight module to provide a plane light source to an LCD panel, the LCD panel converts the plane light source into a color image. However, an user can not clearly see the color image displayed by the transmission LCD apparatus when environment brightness is greater than brightness of the plane light source. Therefore, it is inconvenient for the user to use the transmission LCD apparatus in outdoor during daytime. Moreover, power wastage of the backlight module is nearly 90% of that of the transmission LCD apparatus. However, the back light module operates no matter the transmission LCD apparatus is used in outdoor or indoor. Therefore, the transmission LCD apparatus can not achieve power saving and environmental protection.
Comparing to a transmission display apparatus such as the transmission LCD apparatus, a reflective display apparatus relies on environment light to display. Because the backlight light module is not used in the reflective display apparatus, the reflective display apparatus can achieve power saving and environmental protection. Among various reflective display apparatuses, the electronic paper display apparatus is valued due to its advantages of power saving, thin thickness and flexibility.
However, the reflective display apparatus can not be used when the environment light is not bright enough. To solve the disadvantage, a reflective display apparatus having light emitting components is provided in prior art. The light emitting components of the reflective display apparatus can emit light when the environment light is not bright enough. The light emitting components are light emitting diodes (LEDs) or organic light emitting diodes (OLEDs) and are disposed to surround a display area of the reflective display apparatus.
Although the light emitting components enables the reflective display apparatus can be used when the environment light is not bright enough, the lights provided by the light emitting components can not be uniformly distributed in the display area. Therefore, brightness uniformity of the image displayed by the reflective display apparatus is bad.